Question

At the bank of a river, by measurement, a = 9 ft., b = 15 ft., c = 12 ft., and d = 7 ft.
How long is x?

Answer 1

b/a = x/c

15/9 = x/12

12*15 = 9x

x = 12*15/9

x = 4*15/3

x = 4*5

x = 20